2.1 Welcome to Python
Python was released in 1991 and is an interpreted and dynamically typed language. That first sentence probably makes you want to stop reading and find another topic to learn. However, do not let it intimidate you. Let’s start at the very beginning, a very good place to start!
Way back in the late 1980s, Guido van Rossum designed the Python programming language based upon the ABC Programming Language being used at Centrum Wiskunde and Informatica (CWI) in the Netherlands. It started as a hobby project to keep him busy during Christmas. Rumor has it that he chose the name based upon a BBC famous TV show called “Monty Python’s Flying Circus”. The programming language was released in 1991, with the purpose of helping developers write clear, logical code focusing on readability. You could get your job done with fewer lines of code compared to other languages like C++ and Java.
The language is open source, meaning that no one owns it, everyone can download it for free, and you have access to all the programming statements (source code) used to create the actual Python programming language. Python is an "interpreted" language, meaning that Python code is executed by an interpreter, which reads and runs the code line by line at runtime, rather than being compiled into machine code beforehand. Python is also "dynamically typed," meaning that you don't need to declare the data types of variables explicitly. The interpreter determines the type at runtime, based on the value assigned to the variable.
When a program is written, language statements are used to define the logic necessary to complete a specific task or the goal of the application. Depending on the language, in a compiled programming environment each of the statements are compiled (or converted) from the programming language into a set of machine instructors, often called machine code, that a computer’s processor can execute. In other words, the compiler takes human readable programming statements and converts them into computer readable statements. This sequence of statements (machine instructions) can be executed by the computer’s Central Processing Unit (CPU) directly. An advantage of using a compiled language is that this process makes the execution of the statements or the application very fast.